Eye Care (cont.)

Andrew A. Dahl, MD, FACS

Andrew A. Dahl, MD, is a board-certified ophthalmologist. Dr. Dahl's educational background includes a BA with Honors and Distinction from Wesleyan University, Middletown, CT, and an MD from Cornell University, where he was selected for Alpha Omega Alpha, the national medical honor society. He had an internal medical internship at the New York Hospital/Cornell Medical Center.

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

What types of OTC eye care products are there?

There are eight types of OTC eye care products available.
Each product contains one or more active and inactive ingredients.

Artificial tear drops:
Lubricants (also called artificial tears) are synthetic (manmade), water-based solutions that are used to lubricate the eye and thicken tears. Artificial tears are formulated as solutions or suspensions, varying in viscosity. Popular examples of artificial tears include AquaSite, Bion Tears, Celluvisc, Duratears, Gen Teal, HypoTears, Liquifilm Tears, OcuCoat, Refresh, Systane, Tears Naturale, and TheraTears. Many people develop sensitivity to the preservatives in these solutions, causing increasing redness, burning, or itching. Most of these products are also available in a preservative-free (PF) form. Artificial tears usually are used two to five times a day as needed for relief of symptoms.

Ointments or emollients:
Ointments also are useful lubricants. These products are not water-based and contain lubricating ingredients similar to petroleum jelly. Examples of ointments include Lacri-Lube, Moisture Eyes PM, and Refresh PM. Their advantage over a water-based solution is that they remain in the eye longer. These ointments cause visual blurring immediately after their use. Therefore, they are often used only prior to sleep.

Eye washes: Eye
washes (also known as ocular irrigants) are used to cleanse and/or rinse
debris from the eye. These products are balanced to the proper acidity and
electrolyte concentration so as to be non-irritating to the eye. Washes are
available as liquids or drops. These products may contain boric
acid with sodium borate, sodium phosphate, or sodium hydroxide to maintain
the proper acidity. Examples of washes include AK Rinse, Dacriose, and
Eye-Stream.

Hyperosmotics:
Hyperosmotics are used to treat corneal swelling. Hyperosmotics draw water
out of the cornea and thus reduce corneal swelling. Most OTC hyperosmotics
contain sodium chloride in various concentrations as either a solution or an
ointment. The 2% solution tends to cause less stinging and burning than the
5% solution. An example of a hyperosmotic for corneal swelling is Adsorbonac.

Scrubs:
Eyelid scrubs are useful for removing oils, debris, or loose skin that can be associated with eyelid inflammation. Soap agents provide the foaming action. An example of this type of product is Eye-Scrub.

Decongestants: Decongestants are used to shrink swollen blood
vessels in the congested (red) eye, for example, in conjunctivitis.
Phenylephrine is the most common decongestant for this purpose. Patients at
risk for angle-closure glaucoma should cautiously use phenylephrine because
it can cause an attack of the disease. Rebound congestion, in which blood
vessels become dilated even with continued use of decongestants, is a common
side effect of phenylephrine. Therefore, if no improvement in redness or
symptoms occurs within 72 hours of use, phenylephrine should be
discontinued. A frequent side effect of phenylephrine is dilation of the
pupils. If phenylephrine is absorbed from the eye into the body, an increase
in blood pressure may occur, although this is rare. Nevertheless, patients
with high blood pressure should be cautious in using phenylephrine.
Additionally, if phenylephrine is absorbed, side effects may occur due to
interactions with atropine, tricyclic antidepressants (imipramine), and
monoamine oxidase inhibitors such as phenelzine sulfate (Nardil) or
tranylcypromine sulfate (Parnate), reserpine (Hydropres), guanethidine (Ismelin),
or methyldopa (Aldomet).

A second group of chemical decongestants are the
imidazoles (naphazoline, tetrahydrozoline, and oxymetazoline). Imidazoles
are longer acting than phenylephrine and have fewer side effects, including
rebound congestion. Caution still is recommended with imidazoles because of
the potential for an increase in blood pressure. Of the three imidazoles,
oxymetazoline generally appears to exhibit the least side effects.
Naphazoline may dilate pupils more in people with lightly pigmented (blue
or green) eyes.

Antihistamines: Ocular
antihistamines are available OTC. These antihistamines are combined with
ocular decongestants for the treatment of congestion (conjunctivitis),
particularly when caused by allergy. Pheniramine maleate and antazoline both
block histamine receptors in the eye, and thus provide relief from the
symptoms of itchy, watery eyes. Antazoline may increase pressure slightly in
the eye (of concern to patients with glaucoma) whereas pheniramine maleate
has little effect on pressure. Common side effects of antihistamines include
burning, stinging, and discomfort in the eye. Important side effects that
may be associated with oral antihistamines have not been reported with
ocular antihistamines. Antihistamines should not be used in patients at risk
for developing angle-closure glaucoma. Examples of products that combine an
antihistamine and decongestant are Naphcon A and Ocuhist.

Newer allergy eye-drop preparations: Recently, new classes of eye drops for the treatment of itching due to allergy have become available over the counter. Zaditor, a nonsteroidal anti-inflammatory drop, is an example of these.